Electrical devices often require servicing by a lineman to maintain or repair the electrical devices. In the case of switched electrical devices, an indicator is sometimes provided to indicate to the lineman the condition or position of the contacts, i.e., opened or closed, at any given time. Such indicators are often used in electrical devices with current interrupters such as reclosers.
In a conventional recloser, an internal interrupter assembly is provided within a tank, and an external operating mechanism is mounted to the exterior of the tank to permit a lineman to open and close the contacts of the recloser. Specifically, the external operating mechanism includes an operating arm that is movable between upper and lower positions to manually initiate closing and opening of the contacts of the interrupter within the tank so that a lineman can interrupt current flow through the reclosers when carrying out maintenance on the distribution system. This operating arm can essentially act as a contact position indicator for indicating to the lineman the position or condition of the contacts. However, the operating arm is not always reliable and can be difficult for a lineman to see from a variety of angles when determining the condition of the contacts.
This problem has led to the addition of a separate indicator coupled to the exterior of the recloser tank, which is movable between two positions to indicate the condition of the contacts of the recloser. However, like the operating arm, these indicators are often difficult to see, except if the lineman climbs up the utility pole. Specifically, these prior art indicators are typically flat, planar members with indicia thereon, which are difficult to see unless the lineman is directly in front of the indicator.
Reclosers can be either hydraulically or electronically controlled. Reclosers typically employ a switch box having a lever switch or the like for permitting manually actuated opening and closing of the interrupter contacts. In many of these devices, a separate indicator, as mentioned above, is provided which is movable between two positions to indicate the condition of the interrupter at any given time during operation of the recloser. Closing energy is typically supplied by a relatively large closing solenoid which simultaneously charges one or more opening springs in preparation for a tripping operation. During operation of the known devices, fault currents are sensed by a trip solenoid which initiates tripping of the contacts by releasing the opening springs. Thereafter, a hydraulic or an electronic control mechanism carries out time-delay operations and regulates the number of operating cycles to lock out of the recloser. The operating arm and/or the separate indicator indicates to the lineman the condition of the contacts at any given time during operation of the recloser.
Examples of a single-phase recloser incorporating this construction are the Types D and DV hydraulically controlled, single-phase reclosers marked by McGraw-Edison, while examples of a three-phase recloser of this construction are known from the Types RV, VW and WV reclosers marketed by McGraw-Edison. Examples of reclosers with an electronic control assembly are the Types RVE, VWE, WVE and VSO three-phase reclosers marked by McGraw-Edison. However, all of the contact position indicators of these relcosers are difficult to view from a wide variety of angles.
In view of the foregoing, it is apparent that there exists a need for an electrical contact indicator which will overcome the above problems of the prior art electrical devices. This invention addresses this need in the art along with other needs, which will become apparent to those skilled in the art once given this disclosure.